Basically, I'm working to create a filler task in which subjects solve puzzles (presented as bitmaps and answer with a text response), and which lasts for a particular amount of time.

I want the entire task to last 10 minutes, but I don't want to have a limitation on how long they have for each puzzle before they have to respond. In other words, I'd like to set it up so that they answer as many puzzles as they can in 10 minutes.

I tried setting up a duration parameter for the questionnaire in the .exp file. At first, the dialog box that appears and prompts them to press enter to continue was never made visible to the participants because I couldn't get it to appear in front of the bitmaps. For whatever reason, the bitmaps always wanted to be in front.

Using a countdown (d-600) got around this. The countdown clock was never visible, but the the dialog box moved to the front so that it was visible. The problem now is that following the prompt and pressing enter doesn't do anything--the screen just stays right where it is.

Is there a way to get around this? And are bitmaps always in the front, or is there a way to put other things we want to see in front of them?